By Amy Campbell
Published Winter 2007/08

Harbor seals are a common marine predator here in Puget Sound. In fact, since the passage of the Marine Mammal Protection Act, harbor seal populations have increased tenfold. This raises concerns about how seals could impact protected marine environments where prey species are recovering. Declining salmon stocks have been of particular concern in our region, and often the blame is placed on the seal's appetite for marine fish. Do they eat enough salmon to account for the declining numbers, or might there be other factors involved? What else do seals eat? Does their diet have a negative impact on recovery of depleted species? These are a few of the questions that must be addressed to better understand the harbor seal's influence on marine ecosystems.

Katie Luxa, a graduate student at Western Washington University, is conducting research to help answer some of these questions. Her Master's thesis project focuses on the diet of Pacific harbor seals in Padilla Bay.

Katie Luxa collecting samples at seal haul-out sites via Kayak.

Katie is also studying other aspects of seal foraging habits, such as seasonal variation in diet and variations between the soft-bottomed habitats of Padilla Bay and Drayton Harbor and the rocky habitats of the San Juan Islands.

Sample collection was recently completed and Katie is now working on finishing identification of the prey species. Some of the prey identified so far from the Padilla Bay seals includes Pacific staghorn sculpin, gunnels, snake prickleback, shiner perch, and flatfish. Prey found in the Drayton Harbor samples is similar; however these seals enjoy a greater abundance of Pacific herring and threespine stickleback.   There is more information about Katie Luxa's research.